<gg-chart>

A lit-element component for creating data visualizations using the Grammar of Graphics.

Installation

npm i @brightspaceuilabs/gg-chart

Usage

<script type="module">
  import 'gg-chart/src/gg-chart.js';
</script>

<gg-chart
  data='[{"grade": 82, "timeInContent": 78}, ...]'
  aes="grade, timeInContent"
  geom="point"
  scale='[{"name": "Grades"}, {"name": "Time in Content"}]'
  stats="ymean"
  theme="daylight"
  tooltip="point"
  width="300"
  height="250"
></gg-chart>

Properties

Events

• @gg-chart-point-click -> Point : Event is triggered when a point in the chart is clicked. Parameter is the point with its aesthetic values
• @gg-chart-area-click -> Area : Event is triggered when an area in the chart is clicked. Parameter is the point with its aesthetic values

Attributes

• aes : The charts aesthetics, keys from the data records in axis order. 0 -> x, 1 -> y
• geom : The visual data representation. bar, line, point
• scale : A JSON string that defines the axis names, limits, and breaks.
• stats : Statistical additions, xmean, ymean, bin:{width}
• coord : Coordinate system, polar:x, polar:y, flip
• tooltip : Which elements you want the tooltip to show on, point, area
• pos : Where the geoms should be positioned. stacked, dodged
• theme : The charts styling theme
• legend : Toggles the legend, hidden. Only shows when special aesthetics are used.
• data : The data as a JSON string
• width : The width in pixels
• height : The height in pixels
• .style : A css object for selective styles.

Linting and formatting

To scan the project for linting and formatting errors, run

npm run lint

To automatically fix linting and formatting errors, run

npm run format

Testing with Web Test Runner

To execute a single test run:

npm run test

To run the tests in interactive watch mode run:

npm run test:watch

Tooling configs

For most of the tools, the configuration is in the package.json to minimize the amount of files in your project.

If you customize the configuration a lot, you can consider moving them to individual files.

Local Demo with web-dev-server

npm start

To run a local development server that serves the basic demo located in demo/index.html

Tasks

Proof of Concept

• Draws Axis
• Draws labels and numbers
• Draws headings
• Accepts data
• Keyboard navigable
• Hovering shows tooltips
• Updates when data changes
• Animates when data changes